Enriched environment restores impaired hippocampal long-term potentiation and water maze performance induced by developmental lead exposure in rats.

Lead (Pb2+) exposure in children can induce long lasting deficits in cognitive function and has been modeled in experimental animals. Based on previous studies which demonstrated that learning impairments resulting from developmental Pb2+ exposure were reversible if the animals were provided with an enriched environment, here, we asked if environmental enrichment (EE) could also reverse long-term potential (LTP) impairment induced by lead. Rats drank 1,500 ppm lead acetate (PbAc) solution or distilled water throughout gestation and lactation. After weaning at postnatal Day 22, one half of the control and lead-exposed male offspring were given the environmental enrichment treatment through all the experiments until tested. Electrophysiological and Morris water maze test were performed at 8 weeks of age. The result showed that the impaired learning ability induced by lead could be reversed by EE. Furthermore, our results revealed that EPSP LTP and PS LTP impairments induced by lead were also reversible by EE experience.